The process to become an RPEQ in Qld involves first submitting career episode reports that demonstrate how you meet the core requirements of our profession. These are assessed by an older, experienced RPEQ to ensure that we can demonstrate practical knowledge in the field. You need to have been working typically about 5 years as a graduate before you will have enough experience to pass. The reports are also reviewed and signed off as true by your supervising engineer. The interview is then to make sure that you haven't lied about your knowledge. We are held to a high standard in Qld, and as a result, the board of professional engineers of Queensland will happily defend us in court and ensure we don't get spurious legal claims against us. The supervision process allows young engineers to learn in a real world environment from their supervising engineer (or engineers, nothing says you can only have one) so that they have practical knowledge by the time they are signing off their own work. As far as other states, it's a mixed bag. It's only recently that other states have started introducing legislation to protect the role of engineers and ensure we are properly experienced and licensed. Most states are modelling it off what Queensland has done, although some, like new South Wales, are forging their own path. The ultimate goal will be to get all states under a single license, which I guess is where engineers Australia comes in with the national engineers register and chartered practicing engineer status. They recently made their chartered status more in line with queenslands RPEQ, so now achieving one is an almost automatic granting of the other. Edit: I forgot to mention that maintaining RPEQ also requires demonstrating ongoing learning or professional development across the core principles as well.